In recent years, in order to improve formation accuracy of forming a tire, a method of manufacturing a tire using a rigid inner mold (hereinafter it may be referred to as “inner mold method”) has been proposed (e.g. see Patent Documents 1 and 2.) The rigid inner mold comprises an inner mold body having an outer shape suiting a shape of a tire cavity surface of a vulcanized tire. Onto the inner mold body, tire structure members are sequentially attached so as to form a green tire. The green tire with the rigid inner mold is put into a vulcanizing metallic mold, and the green tire is vulcanized and molded.
As shown in FIGS. 7(A) and 7(B), in the inner mold method, to take out an inner mold body (a) from a vulcanized tire T1, the rigid inner mold body (a) is divided into a plurality of inner mold segments (c) in the circumferential direction. The inner mold segments (c) are pulled out inward one by one and taken out from a bead hole T1a of the tire T1.
However, an inner surface Ts of the vulcanized tire T1 is attached closely to a tire molding surface (as), which is an outer surface of the inner mold body (a). Therefore, it takes a large force F to extract the inner mold segments (c). In the case of forcible extraction, there are risks of damage and deformation in the tire T1 and loss of tire quality. Thus, conventionally it is performed to the increase the division number of the inner mold segments (c), so as to reduce the extracting force F per innermold segment (c) or to pull slowly. However, in this case, it takes a longer time for disassembly extraction operations and incurs reduction in quality.